North Korea sent the confirmation apparently as a warning to aircraft and shipping vessels to stay out of the area of the launch. The missile, a long-range Taepodong-2, is expected to fly above the East Sea, also known as the Sea of Japan, before sending the satellite into orbit.

US Secretary of State Hillary Rodham Clinton and other senior US officials have called on North Korea to cancel plans for the launch, which is seen as a test of a missile that is capable of delivering a nuclear warhead at least as far as Alaska and Hawaii and possibly the West Coast. (For coverage of her recent visit to South Korea, click here.) Special Envoy Stephen Bosworth, visiting China, South Korea, and Japan, called for resumption of six-party talks on North Korea's nuclear program while also decrying preparations for the missile launch.

North Korea, however, has insisted that the sole purpose is to orbit a satellite, just as North Korea claimed to have attempted to do when it launched a Taepodong-1 missile from the same site on Aug. 31, 1998.

That missile aroused consternation – and condemnation – after it flew over the main Japanese island of Honshu, landing in the western Pacific south of Vladivostok. Initial broadcasts said Taepodong-1 had, in turn, launched a satellite airing patriotic songs honoring North Korea’s leader Kim Jong Il and his father, Kim Il Sung, who died in 1994. But the satellite never went into orbit.

North Korea test-fired a Taepodong-2 on July 5, 2006, but the missile crashed into the sea 40 seconds after its launch. North Korea, however, conducted its first – and so far only – nuclear test on Oct. 9, 2006. (For a story about its motives at the time, click here.)

North Korea has warned that any attempt to shoot down Taepodong-2 would be regarded as “an act of war.” Secretary of Defense Robert Gates has said the US is ready to counter any missile that threatens the US. But diplomatic sources have indicated that the US may limit its response to demands for condemnation of the launch in the UN Security Council.